var elements = [
    "Hydrogen",
    "Helium",
    "Lithium",
    "Beryllium"
];

console.log(elements.map(function(element) {
    return element.length;
}));

console.log(elements.map((element) => {
    return element.length;
}))

console.log(elements.map(element => {
    return element.length;
}))

console.log(elements.map(element => element.length))
